Coil and sttppobt fob



Aprll 19.1927. KARAS 1,625,212

COIL AND SUPPORT FOR SAME Filed Feb. 1926 Ha v INSULATION Z% %665/ M ZZ Patented Apr. 19, 1927.

Illl ll'l hiilft A LELAND L. KARAS, OF CHICAGO, ILLINOIS.

COIL AND SUPPORT FOR SAME.

Application filed February This invention relates to improvements in the form and construction of coils for use in electrical apparatus and particularly in radio frequency transformers and the like.

The main objects are to provide a coil support in which the coil is held in. such manner that the space inside the winding is not obstructed so that the coil. windings may be positioned as closely as possible to those of another or mating coil; to provide a coil construction in which the turns of Wire are well protected and securely held in spaced relation to each other and in which the insulating support is entirely eliminated on the inside of the coil and the amount of insulating material in the path of the magnetic flux is reduced; and to provide a construction which can be accurately manufactured at low expense.

An illustrative embodiment of my invention is shown in the accompanying draw ings in which Figure 1 is an elevation of a transformer coil, constructed in accordance with my invention.

Fig. 2 is a perspective view of one of the end rings of the supporting frame of said unit.

Fig. 3 is a perspective view of one of the spacing bars.

' Fig. 4 illustrates the method of construction.

In the form shown the insulating and supporting frame is in the form of a squirrel cage. The conductor coil is mounted inside the frame with the turns held in notches cut in the longitudinal elements or bars of the frame. The frame 1 is preferably of bakelite or similar insulating material. The frame comprises the end rings 2, which are spaced apart by the bars 3, and which are recessed to receive the ends of the bars. The notches I, 011 the inner edge of the bars 3 are inclined and equally spaced to correspond with the pitch of the winding. The bars are identical both as to length and as to arrangement of the notches; and in order to offset the notches in the successive bars to correspond with the spiral of the coil, the series of recesses 5 in the rings are of progressively increasing depth. The rings are duplicates in every detail. When assembled, the, deepest recess in one ring is opposite the shallowest recess in the opposite ring so that the successive bars are properly arranged to fit the coil.

20, 1926. Serial m. 89,626.

In making up the coil, the copper wire is wound on av mandrel 7 to form a helix of the proper length, oitch and diameter. Then the bars 3 are engaged on the u' inding, as illustrated in Figure l. The end rings 2 are then placed in position as described and secured to the spacing bars by means of the screws 8 which thread into the ends of the bars. The ends of the winding are secured to the binding posts 9 on the rings and the completed unit is removed from the mandrel.

The frame is substantial and rigid, and the wire coils are well protected from accidental injury. Also the coils are permanently held in true form, which is quite desirable. The die cost is reduced to a minimum since the rings and the bars are respectively duplicates, and the assembling is simplified because similar parts are inter changeable. The binding posts are similarly located between the deepest and shallowest recesses in the rings, which also facilitates the assembling operation.

lVhile but one specific embodiment of this invention has been herein shown and described, it will be understood that numerous details of the construction shown may be altered or omitted without departing from the spirit of this invention.

I claim:

1. In electrical apparatus, a helical coil, and a supporting cage comprising supporting elements and disposed longitudinally of the coil, said elements being identical and being identically notched to receive and separately support the convolutions of the coil and means for holding said supporting elements in spaced relationship about the circumference of said coil and axially oifset in progressive relationship to each other so that their coil notches will conform to the pitch. of the windings of said coil.

2. In electrical apparatus, a helical coil, and a supporting cage comprising substantially identical supporting elements disposed longitudinally of the coil, said elements being substantially identically notched to receive and separately support the convolutions of the coil, and means for holding said supporting elements in spaced relationship about the circumference of said coil and axially offset in progressive relationship to one another, the sum total of such axial oftsets being equal to the space between the convolutions of said coil.

3. In electrical apparatus, a helical coil,

and a supporting cage comprising supportiug elements located outside of the inner surface of the coil and disposed longitudinally of the coil, said elements being identical and being identically notched to receive and separately support the convolutions of the coil, and end rings notched to receive the ends of said elements, the depths of the last named notches being graduated to locate said elements so that their coil notches will conform to the spiral of the coil.

4. In electrical apparatus an insulating 'lrame comprising end rings connected by spaced bars, said bars being of duplicate form and notched on the inner edges, recesses graduated in depth in the end rings to receive the ends of the spaced bars to progressively vary the relative position of the succeeding notches to accommodate a helical curve and Wire coil mounted on the inside of the frame with the turns held in said notches.

Signed at Chicago this 17th day of February, 1926.

LELAND L. KARAS. 

